Safety-guard for cutting-machines.



. G. E. BENNETT.

SAFETY GUARD'FOR CUTTING MACHINES.

APPLICATION man JAN. 13.4916.

1,226,846. I I Patented-May 22,1917;

. INVENTOR. EE UREEEEENNETT GEORGE E. BENNETT, OF SAN FRANCISCO, CALIFORNIA.

' SAFETY-GUARD FOB currmo-macnmns.

* s ecification letters Patent.

. Patented May 22 1917.

Application fled January 13 1918. Serial No. 71,875.

To all whom it may concern Be it known that I, GEORGE E. BENNETT, a citizen of the United States, residing at San Francisco, in the county of San Fran- ,cisco, State of California, have invented a new and useful Safety-Guard for Cutting- Machines, ofwhich the following is a specification in such full and clear terms as will enable those skilled in the art to construct and use the same.

This invention relates to a punchin press guard to prevent the operator thereo from having the hands under the dies at the time the press is bein operated.

It will be un erstood by those skilled in the art that with operators feeding a punching press rapidly it may often happen that before the fingers have been taken from the die that through some haste or other accident the trip may be operated, whereupon the die will come down and cut off the fingers of the operator, and it is therefore necessary to provide means whereby a suitable guard will come down on the fingers first and at most will give them a slight pinch without allowing the die to be released, and inasmuch as the fingers are not more than three-eighths ofan inch thick when slightly squeezed it becomes necessary for such a releasing device to be operated within as close limits as possible and hence means must be provided for quickly releasing the holding catch while the locking device is being operated throughout the entire movement of .the guard and to effect this means is provided whereby the main lock is not operated until the guard is within one-eighth inch or less of the operating table at the top of the die.

in the drawing in which the same reference numeral is applied. to the same portion throughout, but I am aware that there may be many modifications thereof.

Figure 1 is a side elevation of a presshaving this guard applied thereto, an

Fig. 2 is a front elevation of portion of the press.

The numeral 1 indicates the sub-frame of the punching press 2. The press has the ordinary die table 3 with an upwardly extending post 4 in which the revoluble shaft 5 is mounted. The shaft 5 has a balance wheel the upper .which also acts as the belt pulleyv as indi- An embodiment of the invention is shown sleeve '1 having an eccentric portion at 8 for driving the plunger 9 which is secured to the die head 10. The die head is slidable on guide ways 11 and 12 and carries the die 13. The sleeve 7 is; provided with suitable mechanism for the intermittent operation thereof, said mechanism being held out of operation bythe projecting cam 14 which engages thestop 15. The clutch mechanism 5 'w1th1n the sleeve 7 forms no part of the present invention and is hence not fully shown herein.

The stop 15 is movable verticall and is carried by a plate 16 having lugs l and 18 through which the 'stop 15 projects, a spring 19 holding said stop normallyengaged with the sleeve 7 and projecting cam 14.

At the side of the press there is a plate 20, which plate supports a guard arm 21 which arm has a portion thereof extending across the front of the press and which supports an adjustable plate 22. The plate 22 is held in place on the front end of the lever 21 by means of two set screws 23 and 24, and it is adjustable for the purpose of accommodating it to the various heights of the dies 25 with the attached work table 26, the object being to so adjust the plate 22 as to allow the stop. 15 to be released after the plate 22 has come within one-eighth of an inch or less of the work table 26. i a

At the back end the guard arin is provided with a link 27 which link has a slot at 28 for the operation of the lever 29. The lever 29 is pivoted on the plate 20 at 30 and it is held down at the rear'end normally by means of a rod 31 connected therewith and which rod passes through a lug 32 on the back of the plate 20, a spring 33 assisting in holding the back end of said lever down. At the front of the plate 20 there is pivoted a bell crank lock 34, said lock being connected .with the guard arm by means of a short link '35 while the upper end 36 is in contact with the underside of the forward-end of the lever 29. A link 36 connects the forward end of the lever 29 with the stop 15 and releases said stop at the proper time It will be observed that in order to release the stop 15 it-is necessary for the bell crank lever 34 to ha\7e moved forwardly and its upper end far enough for the lever 29 to miss it, but this movement can only be effected within the very narrow limits previously set.

The operator sits in front of the press and starts the same each time it is desired to punch an article by placing the foot upon the foot edal 40, said pedal, being con- .nected wit the upwardly extending rod 41 whichis in turn connected to the guard arm 21. The rod 41 passes through a lug 42 on theside of the frame and a suitable collar 43 is placed on said rod for the thereby depressing the guard arm 21 at its 'front end and at the same time the up er end of the bell crank lock 34 is moved orwardly until when within the last oneeighth inch of the plate '26 the upper end of the bell crank lock is free from thejron't end of the lever 29. whereupon any further movement of the foot pedal 40- will lift the back end of the lever 29, the pivot pin thereof then bearing upon the slot 28 and will pull the stop 15 down thereby allowing the press to be operated one turn or more as may be desired. If through accident or design the foot pedal happens to be depressed while thehands are still on the table 26 the only thing that can happen will be that the hands will be slightly squeezed because of pressure applied to the foot pedal, but in no event is it possible to start the press in operation until the hands have been removed from the plate 26.

It is to be noted that the principal feature of this invention lies in the fact that the main lock securing the machine against 0 eration is allowed to remain in a perfect y safe position without movement until after the secondary lock has been moved to such. a position as will enable the levers to be operated, but that this cannot be done accidentally so long as the hands happen to be on vthe plate 26.

Having thus described my invention What I claim as new and desire to secure by Letmg, 'a guard extending across the cutting dies, a lever connected with said guard, a foot pedal for depressing the front portion of the guard, suitable levers for operating the stop and thereby releasing the machine to permit it to operate, a secondary lock for j one of said stop levers, a link connected with the secondary lock and with the guard and a slotted rod connected with the guard ever and with the stop operating lever whereby the stop operating lever is operated near the end of the stroke of the uard lever.

2'. A guard for cutting machines com rising the combination of a cutting mac e,

with a stop for preventing it from operating, a link connected with said stop, a lever connected with the link, a secondary lock for said lever, a guard arm pivoted to the frame and having a portion thereof extending across the front of the cutting dies, a slotted rod connecting the guard arm and the first mentioned lever, a link connecting the secondary lock with the guard arm whereby the main stop for the machine is prevented from operating until near the end of the stroke of the guard arm, and suitable connections for depressing the guard arm. 3. A guard for cutting machines com rising the combination with a cutting mac ine, of a movable stop for preventing it from operating, a link connected with said movable stop and with a lever pivoted at the side of the machine, a bell crank lock to prevent the operation of said lever, a ard arm pivoted to the machine and having a slotted link connected with said lever, another link connecting the bell crank lock and guard arm and adaptedto release the first lever near the end of the stroke of the guard arm, and an adjustable guard plate carried on the front of the guard arm.

In testimony whereof I have hereunto set my hand this 6 day of JanuaryA. D. 1916.

GEORGE E. BENNETT.- 

